It is known in the art to break oil-in-water emulsions such as occur in industrial waste waters by adding thereto certain inorganic salts such as zinc chloride and certain types of organic polymers. The inorganic salts act as coagulant aids but heavy metal salts such as zinc chloride are objectionable from the environmental standpoint. Furthermore, the most effective organic polymers that have been employed in the past have been derived from raw materials which are not of uniform quality and hence are not a reliable type of material to provide consistent results.
When attempts are made to combine many of the prior art organic oil-in-water emulsion breaking compositions with an inorganic coagulant aid, a problem arises from the standpoint of compatibility which frequently requires the separate addition of the emulsion breaking organic material and the inorganic coagulant aid. It would be desirable, therefore, to provide a single addition organic-inorganic blend emulsion breaking composition in the form of an aqueous solution containing both the organic polymer and the inorganic coagulant aid dissolved therein so that the solution remains stable against precipitation of the components and at the same time shows excellent activity when used to break oil-in-water emulsions in industrial wastes.
Another disadvantage of some of the more effective emulsion breaking compositions in the past where the organic polymer and the coagulant aid have been combined has been their relatively high pH requirements of 8.5-10 which requires the user to make pH adjustments at the time of addition in the breaking of oil-in-water emulsions.